现在高三的同学们正处在高三复习的关键时刻，学习的效率和品质直接关乎高考的成败。英语更是高考中能够决定成败的一门。下面考高分教育的小编将为大家带来高中英语知识点：主语从句，希望能够帮助到大家。
· 主语从句知识点
▼主语从句的概念与类型
主语从句在复合句中作主句的主语,引导主语从句的词有从属连词that, whether以及连接代词who, what,which, whoever, whatever, whichever和连接副词when, where, why, how等.
例如:
That she was chosen made us very happy.
她当选了使我们很高兴.
What caused the accident is a completemystery.
是什么导致了这次事故还完全是一个谜.
Whether she will come or not is still a question.
她是否来还是一个问题.
Which team will win the match is stillunknown.
哪个队会赢得这场比赛还不知道.
Whoever comes to the party will receive apresent.
参加聚会的每一个人都将收到一份礼物.
When they will start has not been decidedyet.
他们何时出发还没决定.
注意:上述例句中的主语从句都是放在句首,但有时为了使句子结构平衡,避免"头重脚轻",常用it作形式主语,而把从句放在后面.
例如:
It is a pity that she has made such amistake.
她犯了这样一个错误,真是遗憾.
It depends on the climate whether they aregoing shopping today.
他们是否今天去购物还得看天气情况.
这样就构成了下面一些常用句型:
1)It is + adj. / n. +从句
It is a pity/shame that...遗憾的是……
It is possible that...很可能……
It is unlikely that...不可能……
2)It +不及物动词+从句
It seems/appears that...似乎……
It happened that...碰巧……
3)It + be +过去分词+从句
It is said that...据说……
It is known to all that...众所周知……
It is reported that...据报道……
It is believed that...据信……;人们相信……
It is suggested that...有人建议……
It must be pointed out that...必须指出……
It has been proved that...已证明…….
例如:
It is believed that at least a score ofbuildings were damaged or destroyed.
据信,至少有二十座楼房遭到破坏或彻底毁掉.
It is suggested that the meeting should beput off.
有人建议会议延期召开.
It's reported that three people were killedin the accident and five were hurt badly.
据报道,事故中三人丧生,五人重伤.
It is known to all that Taiwan is aninseparable part of China.
众所周知,台湾是中国不可分割的一部分.
